Cooking floor insulation question

[Mark CH]

Howdy All,
After a couple of years lurking around this site and drooling over the various build's I'm about to start on my oven at home. I'm adapting the Pompeii plans to fit where I want my oven and ordering materials to match. My hearth will be made from Hebel Power Panels, which a friend used with excellent results. I'll then lay a Cal Sil board under the cooking floor bricks. My question is, does the Cal Sil board have to run out to the outer edge of the oven or do you cut it to just the shape of the cooking floor bricks?
Any advice appreciated.
Mark CH

[dmun]

Does the Cal Sil board have to run out to the outer edge of the oven?

Your oven should be entirely surrounded by insulation, although in your case you may find the AAC panels, depending on how thick they are, may be enough. I'd run run it out as far as it goes, depending on your finish plans.

[havefun]

sorry guys this is more a question than a reply but not sure how else to post a thread am in the proccess of building my over too n as am not sure what material the fire bricks are made fromnaybe a health hazard? as i wantto cook my bread/pizza direct on the fire bricks they are also £4 75 each n that is NOT cheap at all for me so i be using normal bricks But for insulation bellow the bricks is there any reason not to use thermalite blocks? even the thin ones 4" thick? they do keep the heat very well

Regards n many thx Takis

[david s]

vermicrete is cheaper and insulates better.

[dmun]

Here's a thread about Thermalite brand AAC blocks below the hearth:

http://www.fornobravo.com/forum/f6/t...tion-2527.html (Thermalite aerocrete blocks for hearth insulation?)

They are said to get brittle with repeated heating, but if well enclosed I don't see any problem.

Firebricks are not a health hazard unless you've scavenged used ones from a lead smelter or cupola furnace, where they would pick up heavy metals. They are just clay and alumina, both common cooking materials.

[david s]

I used Hebel power panels on my mobile oven. They are aerated concret with 6mm steel cast into them when manufactured. The panels are 75 mm thick and have cracked. I'm not sure whether they don't like the heat or if they cracked when I hit a speed bump and drove over corrugated roads. Portland cement doesn't like heat and that's what they're made from. Fortunately it doesn't really matter as they are contained in a steel cradle and the whole thing is still holding together ok.

[havefun]

thx guys i just contacted few UK companies all helpful n one company in Yorkshire said they'll get a price for me from their supplier for a round ceramic fire tile to cover all the oven floor by next week If that cost no more than £120 then it be perfect fire bricks will cost almost as much n to have the whole floor covered in one piece its got to be better the space bellow the oven will be used for firewood storage but am a long way off that yet thx all guys u gave me the inspiration to get up n build it

[havefun]

Originally Posted by david s

vermicrete is cheaper and insulates better.

Hi Dave thx for all our suggestions is vermicrete available from builders merchants as i asked couple of them n said never heard of it sorry this is nothing to do with Clay overs, any relation to the brilliant journeyman documentary MAKER? don't tell me he is australian too like John Pilger

anyway the over is slowely moving forwards will post photos after its all done thx all guys for your help

Takis

[david s]

Vermicrete is the name given to the mixture made by combining vermiculite and portland cement ( suggested ratio of 5:1 by volume) It makes a light weight low density insulation that can handle weight on top of it. Suggest you search this site for posts on the stuff.